Circuit maker and breaker.



. LUWENSTEIN L l. BROICH,

URCUH MAKER AND BREAKER,

APPLLCAUON ULEB NCWA 29. 19H5.

Patented Jam. 14, 19N).

2 SHtETS SHEE \N MQ.

wnemw 4 ttoumi,

F. LOWENSTEIN 8:1. BROkCH.

CIRCUIT MAKER ANU BREAKER.

APPLICATION flLED NGV. 29, 1916.

Patented Jan. 14, 19l9 2 SHEETS-SHEEI 2.

vvented certain newand useful FRITZ LOWENSTEIN AND 'JOSEPH BROICH, OF BROOKLYN,

NEW YORK; SAID BROICH ASSIGNOR TO SAID LOWENSTEIN.

CIRCUIT MAKER AND BREAKEB..

Specification of Letters Patent.

Patented Jan. 14, 1919.

Application tiled November 29, 1916. SerialNo. 134,124.

/'o Il lcm/a it may concern Be it known that we, Fnrrz Lownxs'ram and Josnrn Bnortn, citizens of the United States, residing at Brooklyn, county of Kings, and State of New York, have inmprovements in Circuit Makers and Breakers; and we do hereby `declare the following to be a full, vclear,and exact description of the invention, such as willenable others skilled in the art. to which it'appertains to make-and use the same.

'Ilhis invention relates to circuit makers and breakers, and it relates more particularly to relay keys useful in the art of radio 'or wireless communication.

In sending wireless signals, the signal impulses are obtained by making,r and breakmgl an alternating current power supply circuit inductively related to the oscillation circuit or closed circuit of the system, which latter circuit in turn excites the antenna. T he current in the power circuitof the usual l() K. lV. set amounts to 70 or 8O amparos, and in larger sets it is correspondingly heavier, so that there is considerable arcmg when the circuit isbroken. This arcing is very hard on the key terminals or contacts of the circuit-breaking device' employed, which is ordinarily operated by a relay, and in practice a great deal of difficulty is experienced from th'e tendency of the contacts to stick together after they have been in use but a shorttime. W'ith the heavier currents employed in the larger sets, this trouble'is es ecally pronounced. l

n order to minimize the etl'ects of arcing, it is, considered desirable in practice that the key terminals be separated suddenly-and sharply, rather than gradually; and to this end devices have heen proposed wherein the movable terminal is intended to be struck a sharp blow by means of a suitably actuated hammer member, whenl the circuit istobe broken. But devices of this general character heretofore available-in the art havebeen far from satisfactory from apractical standpoint and they have not eliminated the trouble above noted.

The principal object'of -the present in- -ventionv is to overcome the. diliculties nientioned and to provide a key of simple construction, free from the defects character`- izing keys heretofore known, and capable of operating with much larger currents than it the key more or has hei'ore been considered practicable to use with relay keys.

In accordance with the invention the power circuit is made and broken by means of a key device having a movable terminal or contact element carried by an operating member reciprocable by suitable motor means to move said movable terminal into and out of circuit-closing position. By means of a lost motion connection between the-movable terminal and the operating member the latter makes nearly its whole circuit-breaking movement before striking the movable terminal, thus attaining practially maximum velocity beforefimpact and delivering` a sharp hammer blow of high intensity to the movable terminal, which is thereupon suddenly knocked away from the coperating terminal. The arrangement is such that ,the operating member travels only a very smalltdistance after impact, while the movable terminal continues to travel after impact the full distance permitted by the aforesaid lost-motion connection. As will appear hereinafter, this type of construction makes it possible to combine maximuni intensity of hammer blow with maximuln etlicieucy of electromagnetic control, where the operatin member is relay-controlled, as is generally the case.

The` broad principles of the invention above set forth can evidently be embodied in different mechanical constructions; but for the sake of a concrete example, one form which the invention may take and which has proven eminently satisfactory in service is shown in the accompanying drawings, wherw Figure 1 is a plan view of relay key mechanism embodying the principles of the invention;

Fig. 2 is a longitudinal.vertical section, parts being in elevation; and

Figs. 3 'to -C illustrate the operation of less diagrammatieally.

Referring to the drawings, 10 represents a base of suitable insulating material upon which the instrument parts may conven iently be mounted. The key proper for makin, r and breaking the power supply circuit comprises upright stationary metallic terminais 11 secured to the base and providedi with contacts 12. The 'stationary terminals are adapted to be bridged by a movable metallic terminal 13, mountedin a manner to be described later and carrying contacts 1i cooperating with contacts 12. In practice, the contacts 1Q- and 14 may be of silver. The described terminals and contacts con stitutc what are hereinafter termcd contact members which cooperate by direct abutting engagement when in circuit-closing position. Met-al fins 15 serve to dissipate the heat due to arcing. Bin 'ng posts 16 are provided whereby the key device may be connected in the power sup'ily circuit of a wireless transmitter set. will be seen that movement of the bridging terminal away from the compound stationary terminal opens the circuit at two points in series, thus distributn ingthe are-ing effect. hc movable bridging on an aotuatin r rod or plunger 17 which is supported or substantially rectilinear reciprocating move` tent in a bearing provided 'in pedestal 18, and another bearing provided in yoke 19 of -an electromagnet, to be referred to later, which is carried by pedcstals 20. The movable. key terminal 13 is capable of limited sliding movement bodily lengthwise of the actuating rod, such movement being limited on one side by a fixed abutment 2l, and on tlieother by an adjustable abutment. 22, both abutments beingvniounted on the rod. Between said abutnienis the hub 23 o said movable terminal is free to slide. The adjustable abutment may be of any convenient type, but as here shown is in the forni of a nut threaded on the actuating rod and slotted to receive-a split pin 24 which may be inserted .through a transverse hole in the actuating rod, whereby the nut may be held on said rod in any adjusted position.

In the present example, the motor means the r'od or plunger 17 to circuit comprises a relay device including the magnet yoke 1,9 beoremen'tioned, cores 25 and windings 26, the latter being connected to binding osts 27 for connection in a relay circuit including an operating key, not shown. The armature 2S is fast with the` plunger 17 with respect to which the magnet cores are symmetrically disposed, and in the position shown the electroningnet is energized, the armature and rod being drawn int/o their limiting position toward therthe left to close the power supply circuit a rainst. the tension of a spring 29, adjustaby secured as by screw coupling Z50-t0 the rod 17, :indiansliorcd to a posi 31 by 'means of threayled hook-bolt 32, adjusting nut 33 and lock-nut 34. Mo vement of the plunger 17 toward the right is limited by means of adjustable abut.- nient or stop nut 35 which may be similar to abutment 22. Any convenient means may be used to prevent rotation of the movable terminal or contact member 13 on the plunger rod 17 The means here shown comterminal is mounted lbein equal to the width. of sai prises a stud 36 slotted to provide a guide for One of the radiating fins l5.

Assuming the parts to be in the position shown in Figs. 1, Q and 3, with the electromagnet energized to force the movable contact member against the compound station ar contact member and thus to close the circuit controlled by' the key, suppose the circuit energizing the electromagncl to be broken by release of the operating key (not shown). The magnet will thereupon be deiinergized and the plunger rod 17 will be drawn sharply to the right by spring 29. Owing to tlielost motion connection between the lungcr rod and the movable contact mem er, the plunger rod will travel a certain distance, in this instance the major portion of its movement1 before the abutment 21 strikes the hub of the movable contact member, which latter up to this instant therefore remains stationary. The relative position of the parts at this instant is shown diagrammatica ly in Fig. 4. After impact the plunger rod continues to travel a short distance and is 'then arrested by abutment of the stop 35 against the yoke 19, as indicated in Fig. 5. 41n this slight further travel of the plunger rod, the movable contact member is of course carried therewith, but owing to the force of the impact, said movable contact member is driven a further distance, sliding along the plunger rod 17 until it` is'ari'ested by the abutment 22 as shown in Fig. 6. In this position the conseparated by the full tacts 12 and 14 are distance permitted by the parts for the particular adjustment illustrated.

When the operating key in the relay circuit is again closed, the electroniagnet is energized and the plunger rod is drawn back toward the left against the tension of spring Z9 and tlie gap between the contacts 12 and 14 is closed. i

In practice the position ot the armature 28 on the rod 17 is such, and the abutment 22 is so adjusted, that in circuit closing po sition the movable contact member is pnlle firmly against the stationary contact meniber, while the armature 28 does not quite touch the cores Q5. When desired, a disk of paper or the' like (not shown) may be placed between each of the cores 25 of the armature in order to prevent any possibility of theirsticking together. The width of the gap'between the contacts 12 and 14 is adjustable by varying the osition of the stop 35, @je total travel of die lunger rod gap. or the est operation of the mechanism, the plunger rod should travel nearly its entire throw before the abutnientQl strikes the hub of the movable contact member. nlnthis way the rod attains a considerable velocity and can impart to the movable contact meniber a. relatively large amount of energy in the form of a sharp hammer blow. Accordingly, the abntments 21 and 22 should be so located that the lost motion between the plunger rod and the movable contact inem-- ber is slightly less in extent than the total throw of the plunger rod. In a concrete eX- ample, the maximum desired gap between contacts 12 and 1-1, and hence the total throw of the plunger, may beg of an inch; and the movable' contact member may travel ,gli of an inch relative to the plunger rod between the abutments 21 and 22. Under these conditions the plunger rod travels if of an inch in passing from the position illustrated in Fig. 3 to that illustratedv in Fig. t. In Fig. 5 it has traveled 312 o'f an inch farther and has come to rest, while the movable contact member has been carried 31.5 of an inch away from the stationary' contact member, the force of the blow causing it then to continue of an inch farther into the open position ot' Fig. C.

It will be observed that in the construction illustrated, the parts are so constructed and arranged with relation to each other that a maximum hammer effect can be attained with a giveny mass or weight; and furthermore that the construction is of such rigid character that when the #parts have been adjusted in position to give a desired etl'ect, such position is not altered by bending of fiexible parts. This permits of an accuracy of arbustment, and a malntenarncc` of such accuracy, not attainablev in devices heretofore proposed. It will be noted also that this construction makes possible the use ot' a relatively very light but rigid movable Contact member which, in conjunction with the mechanically correct arrangement of the plunger rod whose mass isconcentrated to the best advantage for the end in view, contributes to the efficiency of the hammer effect secured. A farther notable advantage is that an eflicient hammer effect is secured with a very small magnetic move ment of the armature 28.- This evidently.

makes for cqiciency in the electromagnetic control. f

lVhat we claim is 1. In a circuit maker and breaker, the combination, with a stationary Contact member and a movable contact member coperating therewith to make or break a circuit, of means movable in one direction to force said movable Contact member against-said stationary contact member, and'lnovable in an oppositev direction to drive said movable contactmember away from the stationary contact member. the arrangement being such that. in effecting the latter movement, said means travelsl a part of its course independently of said movable contact member, then hits the latter a sharp blow, and then stops, while tnt movable contact member continues to tra vel a predetermined distanceaway from the stationary Contact hmember, the total travel of saidA movable contact membcr and ot' said means being substantially the same. f

2. A circuit maker and breaker comprising, in combination, relatively movable terminals, an actuating member haring a lost motion connection to one ot' said terminals, and reciprocable to move the same into and out of contact with the other terminal, said lost motion connection defining the permissible-relative movement of said terminals` impelling means for said actuating member, and stop means for limiting the movement of sani-actuating member, the arrangement being such that said actuatingr member completes the major portion of' its circuit-la'eaking movement before striking the movable terminal and is then positively stopped, while the movable terminal continues to travel the distance permitted vby the lost motion connection.

3. In a circuit maker and breaker, the combination, `with an electronnignet, a reciprocably mounted plunger rod arranged `to be moved in one direction by said electro- `tion of said stop member .relative to the second of said abutment members being such th'at, .when the electroiiiagiiet is p denergized, the movable Contact member remains stationary until the plungerrod has com- )leted a predetermined major portion of lts total travel permitted bv said stop member, whereupon said movable contact member is struck by such second abutment member, being thereby knocked away from .the

vstationary contact and against the first mentioned abutment member.

4. 'A relay key comprising, in combination, a fixed Contact member, a movable contact -member cooperating, therewith, a. plunger rod carrying said movable contact member, two abutments on saidrod between ,which said movable contact member is bodilyy slidable, an clectromagnct energizable to draw said rod in one direction and thereby to force the movable contact against the fixed contact by means of one ot' said abutments, a springr acting to move said plunger rod in the opposite direction when the electromagnet is dcncrgized and thereby to `cause the second abutment to strike the movable contact member a hammer blow and ttfV electromagnetic device having a pair of cores cooperating with said armature and symmetrically disposed with respect to said rod,

said electromagnetic device acting, when energized, to 'attract said armature and thereby to force said movable contact member into engagement with said stationary contact member through the agency of one of1 said abutments, means operable to move said plungerrod in the opposite direction, when the electromagnet device is denergized, and thereby to cause the second abutment to strike said movable contact member a hammer blow, andmeans for limiting such movement, of the plunger rod,

G. A 'relay key comprising, in combination, a stationary contact member, a rectilinearly'reciprocable plunger rod having a limited throw andprovided with a pair of spaced abutments, a second contact member mounted on said lunger rod and free to slide longitudinal y thereof between said abutments, such sliding movement being limited by said abutmcnts to a distance somewhat less than the throw of said plunger rod, electromagnetic means operating when energized to move said plunger rod into one limitin position and thereby to force said movablle contact member into operative engagement with the stationary contact member through the agency of one of said abutments, and means operable to move said plunger rod sharply into its opposite limiting position upon denergization of said electromagnetic means, and thereby to cause the second' abutment to strike said movable contact member a hammer blow.

7. A relay key comprising, in combination, a stationary contact member, a rectilinearly reciprocable plun er rod having a limited throw and provide with a pair of spaced abutments, a second contact member mounted on said plunger rod and free to slide longitudinally thereof between said abutments, such sliding movement being limited by said abutments to a distance somewhat less than the throw of said plunger rod, electromagnetic means operating when energized to move said plunger rod into one limitin position and thereby tof force said m'ovab e contact member into op- 85 erative engagement with the stationary contact member through the agency of one of said ahutments, and means operable to move' said plunger rod sharply into its opposite limiting position upon denergizatlon of said electromagnetic means and thereby to cause the second abutment to strike said movable contact member a hammer blow, the throw of said plunger rod and the relative positions of said abutments thereon being adjustable.

8. A relay key comprising, in combina y tion, a stationary contact member, a reotilineurly reciprocable plunger rod 'having a throw limited to a minor fraction of an inch, said rod carrying a pair of spaced abutments, a second contact member mounted on said plunger rod and free to slide longitudinally thereofbetween said abut ments, such sliding movement being limited by said abutments, to a distance somewhat less than the throw of said plunger rod, electromagnetic means operating when enerized to move said plunger rod into one limiting position and thereby to force said movable contact member into operative Ven- Y gagement with the stationary contact member through the agency of one of said abutments, and means operable to move said plunger rod sharply into its opposite limiting position upon denergization of said electromagnetic means and thereby to cause thesecond abutment to strike said movable contact member a hammer blow, the throw of said-plunger rod and the relative posiloo tions of said abutments thereon being adjustable.

9. Inl a circuit maker and breaker, vthe combination, with coperating Contact members adapted to make a circuit by direct 106 abutting engagement and to break such cir cuit by relative separating movement which is substantially rectilinear, of means mov able in one direction to effect abutting engagement of said contact members, and mov- 110 able in another direction to separate said contact members substantially rectilinearly, the arrangement being such that in performing the latter movement, said means travels a part of its course independently, then strikes one of said contact members a sharp blow, and then stops, while said contact members undergo a' predetermined rectilinear separation.

In testimony whereof we hereunto aiiix our signatures.

FRITZ LoWENsTEIN. Josera BnoIcH. 

